Touch screens are increasingly being found in all manner of residential and commercial display products. There are several touch screen technologies: analog resistive, digital resistive, substrate capacitive, and projective capacitive and many others. Each technology has its advantages and disadvantages with respect to the competing technologies. Resistive touch screens enjoy the widest latitude for activation method. They can be operated with fingers, a stylus, fingernails, gloved hands, or any object that can apply sufficient pressure to activate the touch substrate. In contrast, projected capacitive touch screens enjoy virtually infinite life, but they can only be activated with a finger, or other conductive object. They do not work well with a generic stylus, and they do not work with all types of gloves. This makes them difficult to use in extremely cold environments, or environments where the operator is wearing gloves. Infra-red touch screens solve the lifetime problem of resistive touch screens, and can be used with gloved hands, or a stylus. However, they can be inadvertently activated by objects passing within the infra-red beam array. For example, if a pencil is held a bit too closely to the display substrate, the infra-red touch panel may record a press event. This foreign object activation is commonly referred to as “fly on the screen” activation and can be problematic in critical control applications for touch screens such as avionic control systems. Projective capacitive, surface capacitive and infrared touch screens require no activation force to enable or select an item with the touch screen, where the resistive type touch screens can be tuned to achieve a particular activation force. The requirement for an activation force is an advantage for the resistive touch screen in critical control applications because the activation force helps to preclude unintended touches by a user.
However, current resistive touch screens typically offer the shortest life span compared to other touch screen technologies. In conventional matrix resistive touch screens, a bottom substrate contains one set of conductive traces and a flexible top substrate contains an array of conductive traces whose orientation is orthogonal with respect to the bottom substrate's conductors. When the top substrate is pressed, the traces of the top substrate are electrically shorted to the traces of the bottom substrate. A controller determines an X-Y position, based on the characteristics of the shorted conductors. However, the top array of conductors is flexed and stretched over repeated pressing of the top substrate and can be damaged over time. The repetitive flexing induces stress cracks in the conductive traces, and eventually causes failure of the touch panel at the cracked locations.